In this study, the catalytic zonation of acid orange 10 (AO-10) in the presence of Au-Bi2O3/Bi2O3 nanocatalysts is investigated. The influence of various effects of the synthetic procedure is evaluated by preparing the Bi2O3 and Au-Bi2O3 catalysts in two different routes. The nanomaterials are characterized through various analytical tools like X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectroscopy. Addition of sonochemically synthesized Bi2O3 and gold nanoparticles loaded sonochemically synthesized Bi2O3 catalysts on ozone assisted catalytic degradation of AO-10 show 1.8-and 3.5-fold enhancement in the degradation rate, respectively. Bi2O3 and gold loaded Bi2O3 samples prepared by sonochemical method provide effective environment for the degradation of AO-10. The total organic carbon (TOC) removal studies performed to understand the mineralization of AO-10 in the presence of various catalysts show that, about 47% AO-10 can be completely abated in 30 min by ozonation in the presence of sonochemically prepared Bi2O3 doped with gold nanoparticles. (C) 2011 Elsevier B.V. All rights reserved.